Aerial JVavigation. 25 



tion of weight to either, or percussion will give it the ascendency. 

 An aerial machine, whose gravitating and ascensive powers are equal, 

 whatever be its size, shape and weight, will, by weight or percussion, 

 move upwards or downwards, as the one or the other of these pow- 

 ers has the ascendency. Therefore its ascent or descent can be ea- 

 sily managed, so as to insure ascent by percussion, and descent by 

 its gravity, the wings being stopped. 



On these principles, an aerial machine of any size, by balancing, or 

 nearly so, its ascensive and gravitating powers, can be made so as to 

 carry any required weight, and it can be governed by percussion ; 

 being once well constructed, it would remain a ready vehicle fitted 

 to move equally in every direction, and there would be no need of a 

 valve to discharge the included air, to enable it to descend, or if there 

 were, it would be used only in case of necessity. The ascensive 

 powers of aerial fluids, lighter than common air, have already been 

 determined, and 1 have made and hung wings on the afored escribed 

 principles, and found their motion very easy and their percussion ve- 

 ry powerful ; therefore ihe practicability, of aerial navigation, can- 

 not be reasonably doubled. The navigation of the air will be at- 

 tended with nearly the same advantages and disadvantages as that of 

 water. The aeronaut, during a storm, is however, less liable to dan- 

 ger than the seaman, as he has the power of descrying it at a great- 

 er distance, and of ascent and descent at pleasure ; he can rise above 

 the danger or descend and anchor fast, or as the wind always 

 moves from or before it, he can take its current, which will bear 

 him from danger, if he keeps sufficiently elevated, while the seaman 

 has no alternative, but either to anchor fast, or if that be impossible, 

 to weather all vicissitudes and dangers. If the aeronaut wishes to 

 move in an opposite direction to the wind, he must rise, (as the at- 

 mosphere is composed of different strata of air, moving at different 

 altitudes, in different directions,) till he finds a favorable current, or 

 wait till the wind in the lower strata blows right, or until it is calm. 

 To what altitude it is possible to ascend on these principles, will de- 

 pend on the balance between the density of the air and the powers 

 of gravity ; for it is evident, that the gravity is directly as the densi- 

 ty. Conveyance by air can be easily rendered as safe as by water or 

 land, and more cheap and speedy, while the universal and uniform 

 diffusion of the air over every portion of the earth, will render aerial 

 navigation preferable to any other. To carry it into effect, there 

 needs only an immediate appeal on a sufficiently large scale, to es-^ 



Vol. XXV.— No. 1, 4 



